Bi-directional associations between healthy lifestyles and mood disorders in young adults: The Childhood Determinants of Adult Health Study

<jats:sec id="S0033291716000738_sec_a1"><jats:title>Background</jats:title><jats:p>Healthy lifestyles prevent cardiovascular disease and are increasingly recognized in relation to mental health but longitudinal studies are limited. We examined bi-directional associations between mood disorders and healthy lifestyles in a cohort followed for 5 years.</jats:p></jats:sec><jats:sec id="S0033291716000738_sec_a2" sec-type="methods"><jats:title>Method</jats:title><jats:p>Participants were aged 26–36 years at baseline (2004–2006) and 31–41 years at follow-up (2009–2011). At follow-up, lifetime mood disorders (depression or dysthymia) were retrospectively diagnosed with the Composite International Diagnostic Interview. A five-item lifestyle score (comprising body mass index, non-smoking, alcohol consumption, leisure time physical activity and healthy diet) was measured at both time points. Linear and log multinomial regression determined if mood disorder before baseline predicted changes in lifestyle (<jats:italic>n</jats:italic> = 1041). Log binomial regression estimated whether lifestyle at baseline predicted new episodes of mood disorder (<jats:italic>n</jats:italic> = 1233). Covariates included age, sex, socio-economic position, parental and marital status, social support, major life events, cardiovascular disease history, and self-rated physical and mental health.</jats:p></jats:sec><jats:sec id="S0033291716000738_sec_a3" sec-type="results"><jats:title>Results</jats:title><jats:p>A history of mood disorder before baseline predicted unfavourable trajectories of lifestyle over follow-up, including somewhat lower risk of improvement [relative risk (RR) 0.76, 95% confidence interval (CI) 0.56–1.03] and greater risk of worsening (RR 1.46, 95% CI 0.99–2.15) of lifestyle independent of confounding factors. Higher lifestyle scores at baseline were associated with a 22% (RR 0.76, 95% CI 0.61–0.95) reduced risk of first episodes of mood disorder, independent of confounding factors.</jats:p></jats:sec><jats:sec id="S0033291716000738_sec_a4" sec-type="conclusion"><jats:title>Conclusions</jats:title><jats:p>Healthy lifestyles and mood disorders are closely related. Our results suggest that healthy lifestyles may not only reduce cardiovascular disease but also promote mental health.</jats:p></jats:sec>